Field
Embodiments of the present disclosure generally relate to semiconductor processing equipment. More particularly, embodiments of the present disclosure relate to a plasma source, an abatement system, and vacuum processing system for abating compounds produced in semiconductor processes.
Description of the Related Art
The processes used by semiconductor processing facilities produce many compounds, such as perfluorinated compounds (PFCs), which are abated or treated before disposal, due to regulatory requirements and environmental and safety concerns. Typically, a remote plasma source may be coupled to a processing chamber to abate the compounds exiting the processing chamber. High density inductively coupled plasma (ICP) may be used as the remote plasma source in abatement of PFCs in some cases.
An ICP remote plasma source may include a coil antenna surrounding a dielectric tube, and the coil antenna may be large enough to surround the entire tube in order to provide the PFCs enough residence time inside the tube. However, a large coil antenna can be impractical since large coil antennas have large inductance, which can cause the power source for the antenna to operate in a non-optimal current-voltage area, leading to “foldback” of the output of the power source due to either a current or voltage limit. As a result, the destruction and removal efficiency (DRE) of PFCs in a conventional ICP remote plasma source typically is around 50%. In addition, as frequency increases, a large inductor, such as the large coil antenna, can carry high potential, causing a more pronounced stray effect (capacitively coupling instead of inductively coupling).
Therefore, an improved plasma source and abatement system is needed for abating compounds in semiconductor processes.